The invention relates to a navigation device, in particular one for installation in a motor vehicle, as specified in the preamble of patent claim 1.
Generic navigation devices with a monitor on which a map may be displayed, especially ones for use in motor vehicles, are widely known. Known from the state of the art are navigation devices in which the scale of a map displayed on a monitor may be modified by operation of push switches. In one of these navigation devices the push switches are in the form of plus and minus keys, so that the display scale can be enlarged or decreased by pressing the appropriate key. So that the user does not lose the proper perspective, the change in scale per key depression stroke is kept small. This, however, results in complicated and sometimes time consuming operation, since the speed with which the scale may be changed by repeated depression of one of the keys is limited. This is undesirable, since the time during which the driver must take one hand off the steering wheel must be minimal.
In another navigation device known from the state of the art a scale may be displayed by a submenu on the monitor; a bar moves on the scale and thus a specific scale can be selected. After confirmation by the user, the map is displayed on the monitor on the scale selected. A navigation device such as this presupposes, however, that before choosing the user will consider his options in order to determine the scale which for him corresponds to the optimum display of the map. A user who has previously acquired little experience with this device, will thus not be able to select the scale corresponding to the display desired. Should the user wish to change scales frequently, this device also seems to be very complicated and not very user-friendly.
In this context the object of the invention is further development of a generic navigation device in such a way that the scale of an image, especially that of a map, may be changed by simple means and as quickly as possible even by an inexperienced user, in the manner desired and with high user friendliness.
This object is attained by a navigation device as specified for the characteristics set forth in patent claim 1. The dependent claims relate to especially advantageous developments of the invention.
It is claimed for the invention that a navigation device is provided in which the change of scale is effected by rotating a rotary switch, one which may be rotated at a speed determined by the user himself. The time required for the change of scale consequently depends only the speed with which the image may be displayed on the monitor on the new scale. In addition, even an inexperienced user can by direct observation of the change of display during rotation of the rotary switch easily find the display scale he desires. The navigation device may thus be characterized as very comfortable and extremely simple to operate. It also presents the advantage that only one operating element is provided and must be found and grasped by the user in order to effect a change of scale.
One advantageous further development of the invention provides that the center of the image is retained during selection of the scale, since the user will instinctively select the visible window on the monitor so that the area of the image of interest to him will be situated almost in the center.
In another operating mode the direction of movement of a cursor on the image may be selected by rotating the rotary switch. While the rotary switch may still be used for other operational functions of the navigation device, for example, in other axial positions, the operating comfort of the navigation device is further increased. Change in the possible direction of movement of the cursor by rotating the rotary switch is especially user-friendly, since the movement to be executed by the user is similar to that of the rotation to be observed on the monitor of the cursor, which is shown as an arrow, for example. In this way adjustment of the direction of movement of the cursor may be extremely flexible, and the user is not limited, as in other devices, to movement in only four or eight different directions, for example, right, left, up and down.
In one further development of the invention, operation of the rotary switch, for example, rotation of the rotary switch or application of axial force to this switch, in another operating mode movement of a cursor may be executed in a selected direction or in the opposite direction or may be canceled, as a result of which operation of the navigation device is further simplified, since the user also does not have to reposition his hand or fingers to move the cursor. If the rotary switch has a plurality of operating modes, this function is preferably linked to the extreme positions of the rotary switch, that is, fully depressed or entirely free of pressure. Initiation or execution of a cursor movement may be carried out before or after setting a direction of movement for the cursor. In the event of initiation of a movement before setting of a direction of movement, preferably the direction of movement most recently set or movement along a previously assigned route or in the direction of a previously entered goal is to be taken as the default direction. The initial direction of the cursor may then be changed during movement of the cursor by rotation of the rotary switch in the direction desired.
If movement of the cursor is initiated by application of axial force to the rotary switch, for a predetermined period of time, for example, the advantage is obtained that, especially during prolonged movement of the cursor in one direction, there is no need for repeated movement of hand or fingers in one direction, but rather the hand or fingers may remain in the same position on the rotary switch during cursor movement.
Provision may also be made such that in another operating mode one function may be selected by rotating the rotary switch. An embodiment such as this renders addition of numerous function keys superfluous and the operating unit of the navigation device claimed for the invention continues to be clearly displayed. The operating mode and/or at least one of the additional operating modes may be selected by means of the function. The operating mode could consequently be selected also by rotating the rotary switch, so that all the operating steps required for use of the navigation device can be carried out with the rotary switch.
Another embodiment of the invention provides that the operating mode and/or at least one of the additional operating modes can be set by actuating at least one of the additional rotary, pressure, and/or slider switches. This embodiment is highly advantageous when the operating mode must be changed very frequently.
In an advantageous development of the invention the operating mode and/or at least one of the additional operating modes may be set by application of axial force over a predetermined period to the rotary switch, preferably against the force of a spring. This development is especially easy to operate if only a few operating modes are used.